How do I animate .pngs?
You don’t. There is a developing standard for “MNG”, Multi-image Network Graphics, with a release version now out. (The MNG homepage is at http://www.cdrom.com/pub/mng/) PSP does not support it,just like they don’t support GIF animation, but Animation Shop (which comes with PSP 5) gives it partial support. In fact, Animation Shop uses a subset of MNG for its default file type. Unfortunately, Animation Shop does not support everything that MNG does, and cannot render some of the sample MNG images available at the MNG homepage.